COVID-19 Information - To see our up to date advice for using our pharmacies - Click Here

Health Knowledge and Encyclopedia

At your local Pearn's Pharmacy we can offer advice on most general health matters. You can also use our Health Encyclopaedia to provide you with the tools and links you need to pinpoint symptoms and get a full explanation of a suspected condition.

Search By Letter
A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y |

Search by Keyword

Pressure ulcers


Pressure ulcers, also sometimes known as bedsores or pressure sores, are a type of injury that affects areas of the skin and underlying tissue. They are caused when the affected area of skin is placed under too much pressure.

Pressure ulcers can range in severity from patches of discoloured skin to open wounds that expose the underlying bone or muscle.

How pressure ulcers develop

Pressure ulcers develop when a large amount of pressure is applied to an area of skin over a short period of time. Or, they can occur when less force is applied but over a longer period of time.

The extra pressure disrupts the flow of blood through the skin. Without a blood supply, the affected area of skin becomes starved of oxygen and nutrients. It begins to break down, leading to the formation of an ulcer.

Healthy people do not get pressure ulcers because they are continuously and subconsciously adjusting their posture and position so that no part of their body is subjected to excessive pressure.

However, people with health conditions that make it difficult for them to move their body often develop pressure ulcers. In addition, conditions that can affect the flow of blood through the body, such as type 2 diabetes, can make a person more vulnerable to pressure ulcers.

See Pressure ulcers - causes for more information about the risk factors that are associated with the condition.

How common are pressure ulcers?

Pressure ulcers are a widespread and often underestimated health problem in the UK and across the world.

It is estimated that just under half a million people in the UK will develop at least one pressure ulcer in any given year. This is usually people with an underlying health condition. For example, around 1 in 20 people who are admitted to hospital with an acute (sudden) illness will develop a pressure ulcer.

People over 70 years old are particularly vulnerable to pressure ulcers due to a combination of factors, such as:

  • reduced blood supply
  • ageing of the skin
  • older people having a higher rate of mobility problems

Two out of every three cases of pressure ulcers develop in people who are 70 years old or more.

Preventing pressure ulcers

Pressure ulcers can be unpleasant, upsetting and challenging to treat. Therefore, healthcare professionals use a range of techniques that are designed to prevent pressure ulcers developing in the first place. These include:

  • regularly changing a person’s position
  • using equipment, such as specially designed mattresses and cushions, to protect vulnerable parts of the body

See Pressure ulcers - treatment and Pressure ulcers - prevention for more information.

Unfortunately, even with the highest standards of clinical care, it is not always possible to prevent pressure ulcers in particularly vulnerable people.


The outlook for someone with pressure ulcers will vary widely among individuals.

For some people, pressure ulcers are a minor inconvenience that require minor nursing care. For others, they are a very serious type of injury that can lead to life-threatening complications, such as blood poisoning or gangrene (a condition where the body’s tissue begins to decay and die).

Treatment for pressure ulcers includes the use of dressings, creams and gels that are designed to speed up the healing process and relieve pressure. For the most serious cases, surgery is sometimes recommended.

^^ Back to top


The parts of the body most at risk of developing pressure ulcers are those that are not covered by a high amount of body fat and are in direct contact with a supporting surface, such as a bed or a wheelchair.

For example, if you are bedbound (unable to get out of bed) you are at risk of developing pressure ulcers on your:

  • shoulders or shoulder blades
  • elbows
  • back of your head
  • rims of your ears
  • knees, ankles, heels or toes
  • spine
  • tail bone (the small bone at the bottom of your spine)

If you are a wheelchair user, you are at risk of developing pressure ulcers on:

  • your buttocks
  • the back of your arms and legs
  • the back of your hip bone

Grading of pressure ulcers

Healthcare professionals use several grading systems to describe the severity of pressure ulcers. The most common is the European Pressure Ulcer (EUPAP) Grading System. The higher the grade, the more severe the injury to the skin and underlying tissue.

Grade one

A grade one pressure ulcer is the most superficial type of ulcer. The affected area of skin appears discoloured and is red in white people, and purple or blue in people with darker coloured skin.

In grade one pressure ulcers, the skin remains intact but it may hurt or itch and it may feel either warm and spongy, or hard.

Grade two

In grade two pressure ulcers, some of the outer surface of the skin (the epidermis) or the deeper layer of skin (the dermis) is damaged, leading to skin loss. The ulcer looks like an open wound or a blister.

Grade three

In grade three pressure ulcers, skin loss occurs throughout the entire thickness of the skin. The underlying tissue is also damaged. However, the underlying muscle and bone are not damaged. The ulcer appears as a deep cavity-like wound.

Grade four

A grade four pressure ulcer is the most severe type of pressure ulcer. The skin is severely damaged and the surrounding tissue begins to die (tissue necrosis). The underlying muscles or bone may also be damaged.

People with grade four pressure ulcers have a high risk of developing a life-threatening infection. 

^^ Back to top


Pressure ulcers develop when sustained pressure is placed on a particular part of the body and interrupts the blood supply to that part of the body.

Blood contains oxygen and other nutrients that are needed to help keep tissue healthy. Without a constant blood supply, tissue damage occurs and the tissue will eventually die.

The lack of blood supply means that the skin no longer receives infection-fighting white blood cells. Once an ulcer has developed, it can become infected by bacteria.

People with normal mobility do not develop pressure ulcers as their body automatically makes hundreds of regular movements that prevent pressure building up on any part of their body.

For example, while you are asleep you may think you are lying still, but you may shift position up to 20 times a night.

The risk factors for pressure ulcers can be divided into one of two categories:

  • intrinsic risk factors – you have an underlying health condition or other factor that makes you more vulnerable to developing pressure ulcers
  • extrinsic risk factors – factors in your immediate environment that put you at risk of developing pressure ulcers

In some cases, a person may have both intrinsic and extrinsic risk factors, which are discussed in more detail below.

Intrinsic risk factors

Intrinsic risk factors for pressure ulcers include:

  • mobility problems – anything that affects your ability to move some or all of your body
  • poor nutrition – for your skin to remain healthy it requires nutrients that can only be supplied by eating a nutritious diet
  • an underlying health condition, which disrupts your blood supply or makes your skin more vulnerable to injury and damage
  • being over 70 years old
  • urinary incontinence and/or bowel incontinence
  • serious mental health conditions

Mobility problems

Possible reasons for having a mobility problem are:

  • having a spinal cord injury that causes some or all of your limbs to be paralysed
  • brain damage caused by an event such as a stroke or severe head injury, which results in paralysis 
  • having a condition that is causing progressive damage to the nerves your body uses to move parts of the body, such as Alzheimer's diseasemultiple sclerosis or Parkinson's disease 
  • having severe pain that makes it difficult to move some or all of your body
  • having a fractured or broken bone
  • recovering from the effects of surgery
  • being in a coma
  • having a condition, such as rheumatoid arthritis, that makes it difficult to move your joints and bones

Poor nutrition

Reasons that your diet may lack nutrition include:

  • anorexia nervosa – a mental health condition where a person has an unhealthy obsession with maintaining a low body weight  
  • dehydration – you do not have enough fluids in your body
  • dysphagia – difficulty swallowing food

Health conditions

Health conditions that can make you more vulnerable to pressure ulcers include:

  • type 1 diabetes and type 2 diabetes – the high levels of blood sugar that is associated with diabetes can disrupt normal blood flow
  • peripheral arterial disease – the blood supply in the legs becomes restricted due to a build-up of fatty substances in the arteries of the legs
  • heart failure – previous damage to the heart means it is no longer able to pump enough blood around the body
  • kidney failure – the kidney loses most or all of its functions; this can lead to a build-up of dangerous toxins (poisons) in the blood, which can cause tissue damage
  • chronic obstructive pulmonary disease (COPD) – a collection of lung diseases; the low levels of oxygen in the blood associated with COPD can make the skin more vulnerable to damage

Ageing skin

There are several reasons why ageing skin is more vulnerable to pressure ulcers. These include:

  • with age, the skin loses some of its elasticity (stretchiness), which makes it more vulnerable to damage
  • reduced blood flow to the skin due to the effects of ageing
  • the amount of fat under the skin tends to decrease as people get older


Both urinary incontinence (inability to control your bladder) and bowel incontinence (inability to control your bowels) can cause certain areas of the skin to become moist and vulnerable to infection. This can trigger pressure ulcers to form.

Mental health conditions

People with severe mental health conditions such as schizophrenia (a condition where people have problems telling the difference between reality and imagination) or severe depression have an increased risk of pressure ulcers for a number of reasons:

  • their diet tends to be poor
  • they often have other physical health conditions, such as diabetes or incontinence
  • they may neglect their personal hygiene, making their skin more vulnerable to injury and infection

Extrinsic risk factors

Extrinsic risk factors for pressure ulcers include:

  • pressure from a hard surface, such as a bed or wheelchair
  • pressure that is placed on the skin through involuntary muscle movements, such as muscle spasms
  • moisture, which can break down the outer layer of the skin (epidermis)

The time it takes for a pressure ulcer to form will depend on:

  • the amount of pressure
  • how vulnerable a person’s skin is to damage

Grade three or four pressure ulcers can develop over short time periods. For example, in susceptible people, a full-thickness pressure ulcer can sometimes develop in just one or two hours. However, in some cases the damage will only become apparent a few days after the injury has occurred. 

^^ Back to top


Diagnosing pressure ulcers 

Pressure ulcers are easily diagnosed by visual examination. However, pressure ulcer management aims to prevent ulcers occurring in the first place. So an important part of the diagnostic process is to assess your level of risk of developing them.

As part of the risk assessment process, the healthcare professionals who are involved in your care will consider:

  • your general health
  • your ability to move
  • whether you have any problems that may affect your posture
  • whether you have any symptoms that may indicate the presence of infection
  • your mental health
  • whether you have had pressure ulcers in the past
  • whether you have urinary incontinence problems controlling your bladder) or bowel incontinence (problems controlling your bowel)
  • your diet
  • how well your blood circulation system is working

As part of the risk assessment, you may be referred for blood and urine tests. Blood tests can be a good way of assessing your general state of health and whether your diet is providing enough nutrition.

Urine tests can be used to check how well your kidneys are working and whether you have a urinary tract infection, which is an infection of the kidneys, bladder or urethra (tube between the bladder and the penis or vulva, through which urine is passed). These types of infection can be a cause of concern if you are incontinent or if you have had spinal damage.


If you are thought to be at risk of developing pressure ulcers but you are not currently staying in a hospital or care home, you may be advised to carry out regular daily checks for evidence of the early signs of the condition.

Look out for areas of discoloration and patches of skin that feel unusually spongy or tough to the touch. Use a mirror to check parts of your body that can be difficult to see, such as your back or buttocks. Contact your GP or your healthcare team if you notice any possible signs of damage.


^^ Back to top


Your care team

Pressure ulcers are a complex health problem arising from many interrelated factors. Therefore, your care may be provided by a team that is made up of different types of healthcare professionals. This type of team is sometimes known as a multidisciplinary team (MDT).

Your MDT may include:

  • a tissue viability nurse (a nurse who specialises in wound care and prevention)
  • a social worker
  • a physical therapist
  • an occupational therapist
  • a dietician
  • medical and surgical experts with experience in pressure ulcer management

Changing position

It is important to avoid putting pressure on areas that are vulnerable to pressure ulcers or where pressure ulcers have already formed. Moving and regularly changing your position helps to:

  • prevent pressure ulcers developing in vulnerable areas
  • relieve the pressure on any grade one or grade two pressure ulcers that have developed

After your risk assessment is completed, your care team will draw up a ‘repositioning timetable’, which states how often you need to be moved. For some people, this may be as often as once every 15 minutes. Others may need to be moved only once every two hours.

The risk assessment will also consider the most effective way to avoid putting any vulnerable areas of skin under pressure whenever possible.

A nurse or physical therapist may also give you training and advice about:

  • correct sitting and lying positions
  • how you can adjust your sitting and lying position
  • how often you need to move or be moved
  • how best to support your feet
  • how to keep a good posture
  • the special equipment that you should use and how to use it

Mattresses and cushions

There are a range of special mattresses and cushions that can relieve pressure on vulnerable parts of the body. Your care team will discuss the types of mattresses and cushions that are most suitable for you.

People who are thought to be at risk of developing pressure ulcers, or who have pre-existing grade one or two pressure ulcers, usually benefit from resting on a specially designed foam mattress, which relieves the pressure on their body.

People with a grade three or four pressure ulcer will require a more sophisticated mattress or bed system. For example, there are mattresses that can be connected to a constant flow of air, which is automatically regulated to reduce pressure as and when required.


Specially designed dressings and bandages can be used to protect pressure ulcers and speed up the healing process. Examples of these types of dressing include:

  • hydrocolloid dressings – these contain a special gel that encourages the growth of new skin cells in the ulcer while keeping dry the surrounding healthy area of skin
  • alginate dressings – these are made from seaweed and contain sodium and calcium, which are known to speed up the healing process

Topical preparations

Topical preparations, such as cream and ointments, can be used to help speed up the healing process and also prevent further tissue damage.


If you have a pressure ulcer, you will not routinely be prescribed antibiotics. Antibiotics are usually only prescribed to treat an infected pressure ulcer and prevent the infection from spreading.

Antiseptic cream may also be applied directly to pressure ulcers to clear out any bacteria that may be present.


Certain dietary supplements, such as protein, zinc and vitamin C, have been shown to accelerate wound healing.

If your diet lacks these vitamins and minerals, your skin may be more vulnerable to developing pressure ulcers. As a result of this, you may be referred to a dietician so that a suitable dietary plan can be drawn up for you.


In some cases, it may be necessary to remove dead tissue from the ulcer to help stimulate the healing process. This procedure is known as debridement.

If there is a small amount of dead tissue, it may be possible to remove it using specially designed dressings and paste. Larger amounts of dead tissue may be removed using mechanical means. Some mechanical debridement techniques include:

  • cleansing and pressure irrigation – where dead tissue is removed using high-pressure water jets
  • ultrasound – dead tissue is removed using low-frequency energy waves
  • laser – dead tissue is removed using focused beams of light
  • surgical debridement – dead tissue is removed using surgical instruments, such as scalpels and forceps

local anaesthetic will be used to numb the area of skin and tissue around the ulcer so that debridement does not cause any pain or discomfort.

Maggot therapy

Maggot therapy, also known as larvae therapy, is an alternative method of debridement. Maggots are ideal for debridement because they feed on dead and infected tissue without touching healthy tissue. They also help to fight infection by releasing substances that kill bacteria and stimulate the healing process.

During maggot therapy, the maggots are mixed into a wound dressing and the area is covered with gauze. After a few days, the dressing is taken off and the maggots are removed.

Many people may find the idea of maggot therapy off-putting but research has found that it is often more effective than more traditional methods of debridement. 


Sometimes, it may not be possible for a grade three or four pressure ulcer to heal. In such cases, surgery will be required to seal the wound and prevent any further tissue damage occurring.

Surgical treatment involves cleaning the wound and closing it by bringing together the edges of the wound (direct closure) or by using tissue moved from a nearby part of the body (flap reconstruction).

Pressure ulcer surgery can be challenging, especially because most people who have the procedure are already in a poor state of health. As a result of the risk factors, a large number of possible complications can occur after surgery, including:

  • infection
  • tissue death of the implanted flap
  • muscle weakness
  • blisters – small pockets of fluid that develop inside the skin
  • recurrence of the pressure ulcers
  • blood poisoning
  • infection of the bone – the medical term for this is osteomyelitis
  • internal bleeding
  • abscesses – painful collections of pus that develop inside the body
  • deep vein thrombosis – a blood clot that develops inside the veins of the leg

Despite the risks, surgery is often a clinical necessity to prevent life-threatening complications of pressure ulcers developing. Such complications include blood poisoning and gangrene (the decay or death of living tissue). 

^^ Back to top



Even with the best possible medical care, complications, which can be occasionally life-threatening, can arise from grade three or grade four pressure ulcers. These complications are discussed below.


Infection can spread from the site of the pressure ulcer to a deeper layer of skin. This type of infection is called cellulitis. It causes symptoms of pain and redness, plus swelling of the skin. It will need to be treated with a course of antibiotics.

See the A-Z topic about Cellulitis for more information.

Left untreated, there is a risk that the infection can spread to the blood (see below) or the underlying bone or joint. In rare cases where pressure ulcers involve the lower back, tail bone and spine, the pressure ulcer can spread to the membranes that surround the spine and brain. This is known as meningitis.

Blood poisoning

If a person with a weak immune system has a pressure ulcer that becomes infected, there is a risk that the infection will spread into their blood and other organs. This is known as blood poisoning, or septicaemia.

In the most serious cases of blood poisoning, damage to multiple organs can lead to a large drop in blood pressure, known as septic shock. Septic shock can be fatal. Symptoms include cold skin and an increased heart beat.

Blood poisoning is a medical emergency. It requires immediate treatment in an intensive care unit (ICU) so that the functions of the body can be supported while the infection is treated with antibiotics or antiviral medication.

See the A-Z topic about Blood poisoning for more information.

Bone and joint infection

Infection can also spread from a pressure ulcer into underlying joints (septic arthritis) and bones (osteomyelitis).

Both of these infections can damage the cartilage, tissue and bone. They may also affect the functioning of the joints and limbs.

Antibiotics are required to treat bone and joint infections. In the most serious of cases, infected bones and joints may need to be surgically removed.

Necrotizing fasciitis

Necrotizing fasciitis, commonly known as ‘flesh-eating’ bacteria, is a serious skin infection that causes rapid tissue death. It can occur when a pressure ulcer becomes infected with a type of bacteria called group A streptococcus bacteria.

Emergency treatment is required. It involves a combination of antibiotics and surgical debridement of the dead tissue.

Gas gangrene

Gas gangrene is a serious but rare form of infection that occurs when a pressure ulcer becomes infected with the clostridium bacteria. The bacteria thrive in environments where there is little or no oxygen. They produce gases and release dangerous toxins. Symptoms of gas gangrene include severe pain and rapid swelling of the skin.

Gas gangrene requires immediate treatment with surgical debridement. In the most serious of cases, it may be necessary to amputate the affected body part to prevent the gangrene from spreading to the rest of the body.

See the A-Z topic about Gangrene for more information

^^ Back to top


As part of your treatment plan, your care team will discuss with you the best way to prevent pressure ulcers. This will be based on your individual circumstances. However, you may find that the general advice outlined below is helpful.

Changing position

Making regular and frequent changes to your position is one of the most effective ways of preventing pressure ulcers. If a pressure ulcer has already developed, regularly changing position will help to avoid putting further pressure on it, and give the wound the best chance of healing.

As a general rule, wheelchair users will need to change their position at least once every 15 to 30 minutes. People who are confined to bed will need to change their position at least once every two hours.

Once you have developed a pressure ulcer, it is important that you minimize or avoid putting any further pressure on it to give the wound the best chance of healing.

If you are unable to change position yourself, a carer or relative will need to assist you. See Pressure ulcers - treatment for more information and advice about positional changes.


Eating a healthy, balanced diet that contains an adequate amount of protein and a good variety of vitamins and minerals can help to prevent skin damage and speed up the healing process. You may be referred to a dietician so that a dietary plan can be drawn up for you.

If you currently have a reduced appetite due to a pre-existing health condition, the advice listed below may be useful.

  • Try eating smaller meals throughout the day, rather than two or three larger meals. Set a timetable for when you should eat, rather than waiting until you feel hungry. This should help to ensure that you receive the necessary nutrition.
  • Avoid drinking large amounts of fluids just before you are about to eat as this will make you feel fuller than you actually are.
  • If you find swallowing difficult, try drinking specially made nutritional drinks or pureed foods and soups.
  • If you are a vegetarian, it is important to eat high-protein alternatives to meat. Cheese, yoghurt, peanut butter, custard, beans and nuts are all good sources of protein.

See the A-Z topic about Diet for information and advice.

Checking your skin

If you have known risk factors for pressure ulcers, it is important that you check your skin on a daily basis for any signs of pressure ulcers, such as discoloured areas of skin. This is particularly important if you have an underlying condition, such as nerve damage or diabetes, which may dampen or numb feelings of pain in certain parts of your body.

You can use a mirror to check the parts of your body that are difficult to see, such as your bottom and the heels of your feet. If you notice any damage, report it to your care team. If you are at home, contact your GP or community nurse. If you are in hospital or a nursing home, inform one of your nurses or carers.

Quit smoking

If you are a smoker, giving up is one of the most effective ways of preventing pressure ulcers. Smoking reduces the levels of oxygen in your blood. It also weakens your immune system, which increases your risk of developing pressure ulcers.

See the A-Z topic about Quitting smoking for further information and advice about giving up smoking.

^^ Back to top
“Pearn's Pharmacies, putting patients first”

Pearn's Pharmacy Services

Common Ailment Service

Primary Choice is a campaign to help the public choose the right health advice in the community.

Tell Me More


Repeat, one-off prescriptions. Collect in store or home delivery.

Sign Up

Funded Services

Browse our NHS funded services offered in our stores.

See Services


We are receiving an increase in the number of requests for delivery of medicines due to the COVID-19 pandemic.

Important Info

Find a GP   

Use our GP locator service and nearest Pearn's Pharmacy Branch

Search Now